wan (wide area network)

WAN (Wide Area Network)

A WAN (Wide Area Network) is a network that covers a broad area (i.e., any telecommunications

network that links across metropolitan, regional, national or international boundaries) using leased

telecommunication lines. Business and government entities utilize WANs to relay data among

employees, clients, buyers, and suppliers from various geographical locations. In essence, this mode of

telecommunication allows a business to effectively carry out its daily function regardless of location. The

Internet can be considered a WAN as well, and is used by businesses, governments, organizations, and

individuals for almost any purpose imaginable.

Related terms for other types of networks are personal area networks (PANs), local area networks

(LANs), campus area networks (CANs), or metropolitan area networks (MANs) which are usually limited

to a room, building, campus or specific metropolitan area (e.g., a city) respectively.

Figure 1 WAN (Wide Area Network)

Figure 2 WAN Terms


CPE (Customer Premises Equipment)- CPE is equipment that’s typically owned by the subscriber and

located on the subscriber premises.

Demarcation Point- The demarcation point is the precise spot where the service provider’s

responsibility ends and the CPE begins. It’s generally a device in a telecommunications closet owned and

installed by the telecommunications company. It’s your responsibility to cable from this box to CPE,

connection would be CSU/DSU or ISDN interface.

Co-Central Office- this point connects the customer’s network to the providers switching network.

Local Loop- The local loop connects the Demark to the closet switching office, which is called Central

Office.

Toll Network- The toll network is a trunk line inside a WAN provider’s network. This network is a

collection of switches and facilities owned by the ISP.

T1 = 1.544 Mbps

E1 = 2.048 Mbps (Europe)

T3 = 44.736 Mbps (45 Mbps)

WAN Connection Type

1. Leased lines- These are referred to as a point to point or dedicated connection. A leased line is a

pre-established WAN communication path that goes from the CPE, through the DCE switch, then

over to the CPE of the Remote site. Allowing DTE networks to communicate at any time with no

setup procedures before transmitting data. When cost is no object, it’s really the best choice. It

uses the synchronous serial lines up to 45 Mbps. HDLC and PPP encapsulations are frequently

used on leased lines.

2. Circuit Switching- When we hear the term circuit switching, think phone calls. The big advantage

is cost. We only pay for the time we actually use. No data can transfer before an end to end

connection is established. Circuit Switching uses dial-up modems or ISDN, and is used for low

bandwidth data transfer.

3. Packet Switching- This is a WAN switching method, which allows us to share bandwidth with

other companies to save money. Packet switching can be thought of as network that’s designed

to look like a leased line yet charges you more like circuit switching. But there is a downside if

you need to transfer data constantly, just forget about this option. Instead, get yourself a leased

line. Packet switching will only really work for you if your data transfers are the busty type – not

continuous. Frame-relay and X.25 are packet switching technologies with speed can range from

56 kbps up to T3 (45 Mbps).


DLCI (Data Link connection Identifier)

Leased Lines – Dedicated Lines (T1-1.544 Mbps, E1-2.048 Mbps)

Circuit Switching- On demand bandwidth between locations. Dial up modems, ISDN.

Packet Switched- Shared, but guaranteed bandwidth between locations Frame-relay, ATM.

WIC (WAN Interface Card)

WIC-1T - One serial port per card (Older)

WIC-2T - Two serial ports per card (Newer)

T1 card - WIC T1 DSU (RJ-45 Female port)

HDLC (High Level Data link control (Cisco proprietary))

PPP (Point to Point (Industry standard protocol))

DB 60 – It would connect one side of WIC T1 and another side would be V.35 CSU/DSU.

LCP (Link Control Protocol)- If the authentication is match then. LCP allows opening connection. If the

username or password would not match then LCP will closed the connection.

Figure 3 WAN Connection Types


PAP (Password Authentication Protocol)- Older version, used to send password in clear text.

CHAP (Challenge Handshake Authentication Protocol)- Password Send in Hash format. We need to

configure the username and password same at both the ends

If the password would not match then LCP sent “trm” sent – means terminate the connection.

CIR (Committed Information Rate)

LAR (Local Access Rate)

LMI (Local Management Interface)- It is a language speak between customer router and service

provider’s router.

PVC (Permanent Virtual Circuit)

DLCI’s are locally significant

Frame Relay PVC Design

1. Hub and spoke

2. Full Mash (Most Expensive)

3. Partial Mash.

4. Multipoint Design (In the same subnet)

5. Point to Point Design (If we use different subnet)

We can use DLCI number 16 to 2007

Router #sh frame-realy LMI

Router #sh frame-relay Map

Router #sh frame-relay PVC

LCP (Link Control Protocol)- A method of establishing configuring maintaining and terminating the point

to point connection. Authentication (PAP, CHAP).

NCP (Network Control Protocol)- A method of establishing and configuring diff network layer protocols

for transport across the PPP link.

Both LCP and NCP are Layer 2 Protocols.

SVC (Switched Virtual Circuits)- Are more likely phone calls. The virtual is established when data needs

to be transmitted after transmission the data, it would be terminated.

DLCCI Values are used on frame-relay interfaces to distinguish between different virtual circuits.


Point to Point- Used when a single virtual circuit connects one router to another. Each Point to Point

subinterface requires its own subnet.

Multi Point- This is when the router is the center of a star of virtual circuits that are using a single

subnet for all routers serial interfaces connected to the frame-relay clouds.

Practical

HDLC

R1 (config) #int s0/0

R1 (config-if) #ip add 192.168.1.1 255.255.255.0

R1#no shut


R2 (config-if) #ip add 192.168.1.2 255.255.255.0

R2#no shut

R1#ping 192.168.1.2

Successful

Figure 4 Cisco HDLC Frame Format

Figure 5 Topology


Here we can see By default HDLC is running on both the routers Serial interfaces. That’s why routers

serial interface is able to ping.

If we want to change HDLC to PPP or Frame-realy, we can change it from it here


R1 (config-if) #encapsulation hdlc/ppp/frame-realy

Now we will use here PPP


R1 (config-if) #ip add 192.168.1.1 255.255.255.0

R1#no shut


R2 (config-if) #ip add 192.168.1.2 255.255.255.0

R2#no shut


R1 (config-if) #encapsulation ppp


R2 (config-if) #encapsulation ppp

Here we can see communication would be established

R1#ping 192.168.1.2 Successful

R2#ping 192.168.1.1 Successful

Now we will apply Authentication here (PAP & CHAP)

R1 (config) #username R2 password cisco

R2 (config) #username R1 password cisco

(Password must match on both sides)


R1 (config-if) #ppp authentication chap


R2 (config-if) #ppp authentication chap

R1#ping 192.168.1.2 successful

R2#ping 192.168.1.1 successful

Figure 6 Topology


Now we will use Frame-Relay

Partial Mesh

Now we will configure first Frame-relay switch

Router (config) #host FRSW

Router (config) #frame-relay switching

FRSW (config) #int s0/0

FRSW (config-if) #encapsulation Frame-Relay

FRSW (config-if) #frame-relay intf-type dce

FRSW (config-if) #clock rate 64000

FRSW (config-if) #frame-relay route 102 interface s0/1 201



FRSW (config-if) #no shut

FRSW (config-if) #Int s0/1

FRSW (config-if) #encapsulation frame-relay


FRSW (config-if) #clock-rate 64000

Figure 7 Topology
















Now we will go on HO Router

Router (config) #host HO

HO (config) #int s0/0

HO (config-if) #ip add 192.168.1.1 255.255.255.0

HO (config-if) #no shut

HO (config-if) #encapsulation frame-relay

Now we will go on Bo1 Router

Bo1 (config) #int s0/0

Bo1 (config-if) #ip add 192.168.1.2 255.255.255.0

Bo1 (config-if) #no shut

Bo1 (config-if) #encapsulation frame-relay












HO # ping 192.168.1.2

HO # ping 192.168.1.3

HO # ping 192.168.1.4

Successful

Bo1#ping 192.168.1.1

Successful

Bo1#ping 192.168.1.3

This will not ping, because this is partial mash. It will only ping HO.

Now on HO

HO #sh frame-realy pvc

HO #sh frame-relay map

Here we will see three map

Now on Bo1

Bo1#sh frame-relay map

Here we will see only one.

Fully Mash

We will make it fully mesh now.

Figure 8 Topology











FRSW (config-if) #do sh history

Now on Bo1


Here we will see all three entries

Bo1#ping 192.168.1.3

Bo1#ping 192.168.1.4

Successful


Here we see all three entries

Bo2#ping 192.168.1.2

Bo2#ping 192.168.1.4

Now we will make it once again partial mash


FRSW (config-if) #no frame-relay route 203 interface s0/2 302


FRSW (config-if) #int s0/2



FRSW (config-if) #int s0/3



Now it is once again Partial mesh

Here we will use different subnets between HO and Bo.

Here we will change the IP of Bo3





Now Bo3 should not ping with the HO.

Here we will make some changes on HOs router.

HO (config) # int s0/0

HO (config-if) #no ip add

HO (config-if) #encapsulation frame-relay


Now here we will create sub interfaces

HO (config) #int s0/0.1 multipoint

HO (config-subif) #ip add 192.168.1.1 255.255.255.0

HO (config-subif) #frame-relay interface-dlci 102

HO (config-fr-dlci) #frame-relay interface-dlci 103

HO (config) #int s0/0.2 point to point

HO (config-subif) #ip add 10.1.1.2 255.255.255.0

HO (config-subif) #frame-relay interface-dlci 104

HO # sh frame-relay map

Serial0/0.1 (up): ip 192.168.1.2 dlci 102(0x66,0x1860), dynamic, broadcast,, status defined, active

Serial0/0.1 (up): ip 192.168.1.3 dlci 103(0x67,0x1870), dynamic, broadcast,, status defined, active

Serial0/0.2 (up): point-to-point dlci, dlci 104(0x68,0x1880), broadcast status defined, active

HO #ping 192.168.1.2

HO #ping 192.168.1.3

HO #ping 10.1.1.1

All successful

Now here we will create static map between Bo1 and Bo2

Bo1#Ping 192.168.1.3

It would not ping, because it has only the connectivity with HO.



Bo1 (config-if) #frame-relay map ip 192.168.1.3 201


Bo2 (config-if) #frame-relay map ip 192.168.1.2 301



We would see here two entries

Bo1#ping 192.168.1.3

Bo1#ping 192.168.1.1

Bo1#traceroute 192.168.1.3

Now we will perform routing between HO and Bo

HO (config) #int fa0/0

HO (config-if) #ip add 192.168.101.1 255.255.255.0


HO (config-if) #router ei 100

HO (config-router) #network 0.0.0.0

HO (config-router) #no auto summary

Now on Bo

Bo1 (config) #int fa0/0



Bo1 (config-if) #router ei 100

Bo1 (config-router) #network 0.0.0.0

Bo1 (config-router) #no auto summary

HO#sh ip route

HO#sh frame-relay PVC

wan (wide area network)

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